Ethylenediamine-functionalized superparamagnetic carbon nanotubes for magnetic molecularly imprinted polymer matrix solid-phase dispersion extraction of 12 fluoroquinolones in river water

A novel fluoroquinolone molecularly imprinted polymer (MIP) on the surface of ethylenediamine-functionalized magnetic carbon nanotubes (EDA@Mag-CNTs-MIP) was synthesised. The properties of the EDA@Mag-CNTs-MIP were characterized by using a transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). With using EDA@Mag-CNTs-MIP as the adsorbent, a simple and sensitive method based on the use of a magnetic molecularly imprinted polymer matrix solid phase dispersion extraction (Mag-MIP-MSPD) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) was developed to determine 12 fluoroquinolones in river water. Fluoroquinolones adsorbed with EDA@Mag-CNTs-MIP could be simply and rapidly isolated through a magnetic field, and the main factors, i.e., the pH value and sample volume, affecting the extraction were investigated in detail. Under optimal experimental conditions, the enhancement factor of the Mag-MIP-MSPD procedure was 100 times. The obtained results demonstrated the higher extraction capacity of EDA@Mag-CNTs-MIP with recoveries between 80.2 and 116%. The limits of quantification (LOQs) for the fluoroquinolones were between 0.26 and 1.78 ng L-1. The developed Mag-MIP-MSPD UFLC-MS/MS method had been successfully applied to sixty real samples, and it was confirmed that the EDA@Mag-CNTs-MIP was a kind of highly effective Mag-MIP-MSPD material for fluoroquinolone analyses.